Around 50 anti-racism campaigners gathered in Swansea on Sunday to deliver leaflets opposing fascism.
A leaflet opposing fascism was dropped at homes in Swansea
Campaigners said it was in response to a leaflet drop by the British National Party (BNP) opposing plans for a new mosque to be built in the city.
The Muslim community want to open a new mosque in the former St Andrews United Reformed Church.
But the plans were opposed by the BNP who said it wanted to stop the "Islamification" of Swansea.
On Wednesday, South Wales Police confirmed that following complaints, they were looking at the contents of leaflets handed out by BNP members - including party leader Nick Griffin - about the plans for the mosque in the former church in George Street.
According to the BNP's website, around 1,000 leaflets have been posted to homes in the Castle ward.
The BNP dropped leaflets opposing plans for a new mosque
The BNP website carries a photograph of Mr Griffin - who lives near Welshpool, mid Wales - delivering the leaflet.
The party has denied trying to stir up hatred of any race or religion, but has argued it should be able to debate the mosque issue without fear of arrest.
Anti-racism group Swansea Unite Against Fascism (UAF) organised a counter mailshot campaign on Sunday.
The group dropped leaflets at homes in the Sandfields area of the city.
Martin Chapman, the chairman of the group said that around 1,500 leaflets were delivered to homes in the area.
"It didn't take us long to do because there were so many people who wanted to help," he said.
"We are going to continue to fight against any attempts to divide our community," he added.
Swansea's Muslim community bought the former church, just across the road from the existing mosque in St Helen's Road, in the late 1990s.